Dwarf Ixora Diseases

Dwarf ixora produces orange, red, pink or yellow blooms.

The dwarf ixora (Ixora taiwanensis), also called dwarf flame of the woods, is a compact shrub reaching heights between 8 to 10 inches. Its small stature makes this miniature shrub a smart choice for gardens with limited space in U.S. Department of Agriculture plant hardiness zones 9 through 11. Even though these colorful, tropical shrubs are easy to maintain, they are susceptible to a few diseases.

Anthracnose

Anthracnose, a fungal infection, attacks various evergreen and deciduous shrubs and trees, including dwarf ixora. This disease occurs in humid, wet weather and causes black, tan or red spots to develop on the foliage. The infected leaves will start to wilt, yellow and fall from the plant, and blackish cankers may appear on the stems. Controlling anthracnose with fungicides is not recommended, states the University of California Statewide Integrated Pest Management Program, so change how you care for the plant instead. When possible, remove infected branches, twigs and leaves during the fall and winter, and avoid watering methods that wet the leaves.

Leaf Spot

Leaf spot disease is the result of various fungal pathogens that cause discolored spots, raised areas or brownish yellow patches on the leaves of infected plants. In severe cases, the leaves may fall from the ixora, but the long-term damage is rare. The symptoms of leaf spot disease are sometimes confused with signs of a bacterial pathogen or insect infestation. If the ixora is healthy and vigorous, the plant can tolerate leaf spot disease with no lasting damage. Prevent this fungal disease by avoiding over-watering and removing plant matter that has fallen to the ground.

Sooty Mold

Sooty mold is a nasty-looking fungus that has a black, sootlike appearance. Thankfully, this problem rarely causes long-term injury or serious damage to a dwarf ixora. Sooty mold occurs when sap-sucking pests -- such as aphids, scale insects, whiteflies and mealybugs -- secrete a sticky substance known as honeydew. The mold grows on the honeydew, making the plant appear black. Treating this fungal growth requires eliminating the insects secreting the honeydew. Neem oil, insecticidal soap and horticultural oil will control the insects infesting the dwarf ixora shrub. The sooty growth can be washed off the plant with a hose.

Root Rot

Mushroom root rot -- also known as Armillaria root rot -- attacks and kills the vascular tissue known as cambium. Once the cambial tissue dies, the roots will die. Above-ground symptoms include leaf dropping, branch dieback, discolored stems and cankers. As the fungal disease progresses, mushroom clusters will begin to grow at the base of the plant. Mushroom root rot is a fatal problem for plants and occurs in soggy soils with poor drainage. The best defense against root rots is to prevent the fungus from taking hold by only planting in well-drained soils.

About the Author

Marylee Gowans has written about gardening for both online and print publications. She attended the University of Akron, graduating with a Master of Fine Arts in creative writing. In 2009, she received master gardener certification from the Master Gardeners of Summit County, Ohio.